This is a two-part study (A&B) designed to evaluate the safety and tolerability of commitant LY333013 and methotrexate administration in rheumatoid arthritis patients. Each part of this multicenter study will be conducted independently and will consist of a single blind, placebo controlled, randomized two period crossover. LY333013 is a prodrug of LY315920 which is a potent inhibitor of human non-pancreatic secretory phospholipase A2 (sPLA2). LY333013 is being developed for oral administration in patients with chronic inflammatory conditions such as rheumatoid arthritis, osteoarthritis, asthma and chronic bronchitis.